Forming of additively manufactured product

ABSTRACT

An exemplary process includes determining a desired pore size, selecting an initial pore size greater than the target pore size, manufacturing a porous structure with the initial pore size, forging the porous structure to form a forged part having the desired pore size, and forming an orthopedic device from the forged part.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/676,413 filed Aug. 14, 2017, which claims the benefit ofU.S. Provisional Patent Application No. 62/374,611, filed on Aug. 12,2016, the contents of each application hereby incorporated by referencein their entirety.

TECHNICAL FIELD

The present disclosure generally relates to porous structures, and moreparticularly but not exclusively relates to methods of making suchporous structures using both additive manufacturing techniques andmechanical forming techniques, such as forging and/or rolling.

BACKGROUND

Additive manufacturing techniques are increasingly being used to producemedical devices, as such techniques typically enable the production ofcomponents having both porous portions (e.g., in regions where tissuein-growth is desired) and solid portions (e.g., in regions where greaterstructural strength is needed). Although additive manufacturing hassignificant advantages, such as enabling the porous sections to bemanufactured with porosities and pore sizes tailored to a particularapplication, these techniques are not without their challenges. Forexample, while laser additive manufacturing techniques can typicallyproduce much finer pores as compared to electron beam techniques, bothapproaches generally have difficulty in producing interconnecting poresthat are smaller than a threshold size. This threshold size partiallydepends upon the size of the powder used as a raw material (typically inthe range of 40 microns to 100 microns), and partially depends upon thesize of the melt pool generated by the beam (typically in the range of25 microns to 100 microns, depending on beam power, spot size, and scanspeed).

In addition, smaller pores may trap fine powder which can be difficultto remove during the cleaning process. Although these smaller pores maybe unsuitable for tissue in-growth, they may be suitable to partiallyinfiltrate polymeric compositions to produce components formusculoskeletal articulating and non-articulating surfaces. Whenpolymeric compositions are infiltrated in larger pores, there is a riskof the polymeric composition infiltrating through the entire thicknessof the porous part, thereby clogging the pores that are typicallyprovided to promote tissue in-growth. Another challenge associated withadditive manufacturing is the time it takes to produce the porouscomponents, as the computing and printing time can be significantlylarger for structures with smaller pores than for those with largerpores.

Certain existing approaches have attempted to overcome these challengesby tailoring parameters of the additive manufacturing process itself.For example, certain approaches to preventing undesired infiltration ofpolymeric compositions include providing a thicker cross-section of themetallic portions of the manufactured product, or creating a gradient inthe pore sizes. However, these approaches can produce additionalchallenges, such as those associated with providing tissue-conservingdevices where minimal amount of metal and polyethylene is required, orwhere a thicker cross-section of polyethylene is required. One currentapproach to reducing the printing time is to increase the beam power andscan speed, such that a thicker layer is built on each pass. However,this approach comes with the challenge of increasing the size of themelt pool, and thus may further reduce the ability to produce finerpores. For these reasons among others, a need remains for furtherimprovements in this technological field.

SUMMARY

An exemplary process includes determining a desired pore size, selectingan initial pore size greater than the target pore size, manufacturing aporous structure with the initial pore size, forging the porousstructure to form a forged part having the desired pore size, andforming an orthopedic device from the forged part. Further embodiments,forms, features, and aspects of the present application shall becomeapparent from the description and figures provided herewith.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic flow diagram of a process according to certainembodiments; the flow diagram is split into two portions, designatedFIGS. 1a and 1 b.

FIG. 2 is a schematic block diagram of a system that may be utilized inconnection with the process illustrated in FIG. 1.

FIG. 3 is a schematic representation of a modeling device that may beincluded in the system illustrated in FIG. 2

FIG. 4 is a schematic representation of an additive manufacturing devicethat may be included in the system illustrated in FIG. 2.

FIG. 5 illustrates an embodiment of a porous structure formed using theadditive manufacturing device illustrated in FIG. 4; the inset of FIG.5a is an enlarged view of a portion of the porous structure.

FIG. 6 is a schematic representation of a heat treatment device that maybe included in the system illustrated in FIG. 2.

FIG. 7 is a schematic representation of a forging device that may beincluded in the system illustrated in FIG. 2.

FIG. 8 illustrates an embodiment of a forged part, which is formed fromthe porous structure illustrated in FIG. 5; the insets of FIGS. 8a and8b are enlarged views of portions of the forged part.

FIG. 9 is a cross-sectional illustration of a portion of the forged partillustrated in FIG. 8.

FIG. 10 is a schematic representation of a molding device that may beincluded in the system illustrated in FIG. 2.

FIG. 11 is a cross-sectional illustration of a portion of a molded partformed from the forged part illustrated in FIGS. 8 and 9.

FIG. 12 is a schematic representation of a machining device that may beincluded in the system illustrated in FIG. 2.

FIGS. 13a and 13b are schematic representations of orthopedic devicesthat may be formed using the process illustrated in FIG. 1.

FIG. 14 is a cross-sectional illustration of an acetabular cup accordingto certain embodiments.

FIG. 15 is a schematic representation of a molding device being utilizedin a process of creating the acetabular cup illustrated in FIG. 14.

FIG. 16 is a schematic representation of a femoral implant according tocertain embodiments.

FIG. 17 is a schematic block diagram of a computing device which may beutilized in connection with certain embodiments.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates.

References in the specification to “one embodiment,” “an embodiment,”“an illustrative embodiment,” etc., indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may or may not necessarily includethat particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. It shouldfurther be appreciated that although reference to a “preferred”component or feature may indicate the desirability of a particularcomponent or feature with respect to an embodiment, the disclosure isnot so limiting with respect to other embodiments, which may omit such acomponent or feature. Further, when a particular feature, structure, orcharacteristic is described in connection with an embodiment, it issubmitted that it is within the knowledge of one skilled in the art toimplement such feature, structure, or characteristic in connection withother embodiments whether or not explicitly described.

Additionally, it should be appreciated that items included in a list inthe form of “at least one of A, B, and C” can mean (A); (B); (C); (A andB); (B and C); (A and C); or (A, B, and C). Similarly, items listed inthe form of “at least one of A, B, or C” can mean (A); (B); (C); (A andB); (B and C); (A and C); or (A, B, and C). Further, with respect to theclaims, the use of words and phrases such as “a,” “an,” “at least one,”and/or “at least one portion” should not be interpreted so as to belimiting to only one such element unless specifically stated to thecontrary, and the use of phrases such as “at least a portion” and/or “aportion” should be interpreted as encompassing both embodimentsincluding only a portion of such element and embodiments including theentirety of such element unless specifically stated to the contrary.

In the drawings, some structural or method features may be shown inspecific arrangements and/or orderings. However, it should beappreciated that such specific arrangements and/or orderings may not berequired. Rather, in some embodiments, such features may be arranged ina different manner and/or order than shown in the illustrative figuresunless indicated to the contrary. Additionally, the inclusion of astructural or method feature in a particular figure is not meant toimply that such feature is required in all embodiments and, in someembodiments, may be omitted or may be combined with other features.

With reference to FIGS. 1-13, illustrated therein are a process 100 anda system 200 which may be utilized to manufacture a product, generallyindicated with 300-series reference characters. More specifically, FIG.1 is a schematic flow diagram of a process 100 according to certainembodiments, FIG. 2 is a schematic block diagram of a system 200according to certain embodiments, and FIGS. 3-13 illustrate variouscomponents of the system 200 and stages of the product progressing froma unit cell 310 (FIG. 3) to a finished orthopedic device 370 (FIG. 13).Operations illustrated for the processes in the present application areunderstood to be examples only, and operations may be combined ordivided, and added or removed, as well as re-ordered in whole or inpart, unless explicitly stated to the contrary. Unless specified to thecontrary, it is contemplated that certain operations or steps performedin the process 100 may be performed wholly by one of the devicesillustrated in connection with the system 200, or that the operations orsteps may be distributed among one or more of the devices and/oradditional devices or systems which are not specifically illustrated inFIGS. 2-12.

The illustrated form of the process 100 generally includes a modelingprocedure 110, an additive manufacturing procedure 120, a heat treatmentprocedure 130, a forging procedure 140, a molding procedure 150, amachining procedure 160, and a finishing procedure 170, one or more ofwhich may be omitted in certain embodiments. Additionally, theillustrated system 200 generally includes a modeling device 210, anadditive manufacturing device 220, a heat treatment device 230, adeforming device in the form of a forging device 240, a molding device250, a machining device 260, and a finishing device 270, each of whichmay be utilized in connection with a corresponding one of the procedures110-170. As will be appreciated, one or more of the devices 210-270 maybe omitted from the system 200, for example in embodiments in which thecorresponding one of the procedures 110-170 is omitted from the process100. The system 200 may further include a control system 290 or network,which may be in connected with one or more of the devices 210-270 tocontrol the devices and/or provide communication between the devices.

As described in further detail below, the modeling procedure 110involves generating one or more models using the modeling device 210,and the additive manufacturing procedure 120 involves utilizing theadditive manufacturing device 220 to manufacture a porous structure 320,which includes at least one porous portion 324 having a plurality oforiginal or initial pores 329 (FIGS. 4 and 5). The heat treatmentprocedure 130 generally involves heat treating the porous structure 320with the heat treatment device 230 (FIG. 6), and the forging procedure140 involves utilizing the forging device 240 on the porous structure320 to form a forged part 340, which includes a deformed layer 346having modified pores 349 and a second layer 347 (FIGS. 7-9). Themolding procedure 150 involves utilizing the molding device 250 to forma molded part 350 including the forged part 340 and an attached part 355(FIGS. 10 and 11), and the machining procedure 160 involves utilizingthe machining device 260 to form a machined part 360 from a workpiece163 (FIG. 12), such as the forged part 340 or the molded part 350.Additionally, the finishing procedure 170 involves utilizing thefinishing device 270 to form a finished orthopedic device 370 from anunfinished orthopedic device 173, such as the forged part 340, moldedpart 350, or machined part 360.

With specific reference to FIGS. 13a and 13b , the orthopedic device 370includes a body portion 371 having a tissue-facing region 372 and anopposite second region 374. More specifically, the body portion 371 isformed of the forged part 340, and each of the body portion regions 372,374 is formed of one of the forged part layers 346, 347. In certainforms (FIG. 13a ), the tissue-facing region 372 may be formed of thedeformed layer 346, and the second region 374 may be formed of thesecond layer 347. In other forms (FIG. 13b ), the second region 374 maybe formed of the deformed layer 346, and the tissue-facing region 372may be formed of the second layer 347. In such embodiments, the device370 may further include a polymeric portion 375, which is formed of theattached part 355 and has a smooth surface 376. In certain embodiments,the polymeric portion 375 may be an articular portion, and the smoothsurface 376 may be an articular surface. In other embodiments, thesmooth surface 376 may not necessarily be an articular surface, and mayinstead be configured to discourage attachment of soft tissue to thepolymeric portion 375. By way of example, an orthopedic device 370including the polymeric portion 375 may be provided in the form of aresurfacing acetabular or tibial device.

The process 100 may begin with an operation 102, which generallyincludes determining or selecting a target porosity characteristic 103based upon at least one criterion 101. More specifically, the operation102 includes determining the target porosity characteristic 103 for thedeformed layer 346 of the forged part 340, and the criteria 101 mayrelate to a desired performance characteristic for the deformed layer346. As noted above, the deformed layer 346 of the forged part 340corresponds to one of the regions 372, 374 of the orthopedic device 370.Accordingly, the operation 102 may alternatively be considered toinvolve determining the target porosity characteristic 103 for thecorresponding one of the regions 372, 374. The target porositycharacteristic 103 may, for example, include one or more of a targetaverage pore size 103 a, a target range 103 b of pore sizes, and atarget porosity fraction 103 c for the deformed layer 346. In certainembodiments, the target pore size range 103 b may be related to thetarget average pore size 103 a, or the average pore size 103 a may bedefined as the average of the target range 103 b.

In certain embodiments, the criteria 101 may include a tissue in-growthcriterion, and the target porosity characteristic 103 may be selected topromote tissue in-growth in the porous region 374. For example, a targetporosity characteristic 103 based upon such a criterion may include atarget average pore size 103 a of less than 1000 microns and/or aporosity fraction 103 c in the range of 35% to 70%. The target porositycharacteristic 103 may additionally or alternatively include a targetrange 103 b of pore sizes. For example, such as a range 103 b may have alower limit between 50 microns and 300 microns and/or an upper limitbetween 500 microns and 1000 microns.

In certain embodiments, one or more of the criteria 101 may relate toinfiltration of a polymeric composition, and the target porositycharacteristic 103 may be selected to provide a desired level ofinfiltration during the molding procedure 150, or a desired degree ofcontrol over such infiltration. For example, a target porositycharacteristic 103 based upon such a criterion 101 may include a targetaverage pore size 103 a of less than 500 microns and/or a porosityfraction 103 c in the range of 15% to 35%.

In certain embodiments, the operation 102 may further includedetermining at least one additional target porosity characteristic 103′,such as for a second porous region of the orthopedic device 370. Furtherdetails regarding exemplary selections for the target porositycharacteristics 103, 103′ are provided below.

The process 100 also includes an operation 106, which includes selectingan initial porosity characteristic 107 for at least one porous portion324 of the porous structure 320 based upon at least one criterion 105.As described in further detail below, the forging procedure 140generally involves deforming at least one portion 324 of the porousstructure 320 to form a forged region 344 including a deformed layer346. As a result of the forging, the deformed layer 346 has a smalleraverage pore size and a lower porosity than the corresponding portion324 of the initial part 320. Accordingly, one of the criteria 105 mayrelate to the target porosity characteristic 103, and the operation 106may include selecting an initial porosity characteristic 107 greaterthan the target porosity characteristic 103. For example, the operation106 may include selecting one or more of an initial average pore size107 a greater than the target average pore size 103 a, an initial poresize range 107 b higher than the target pore size range 103 b, and aninitial porosity fraction 107 c greater than the target porosityfraction 103 c. As described in further detail below, selection of theinitial porosity characteristic 107 may affect and be affected by theoperating parameters associated with the additive manufacturingprocedure 120. Accordingly, one or more of the criteria 105 may relateto the additive manufacturing procedure 120 and/or the additivemanufacturing device 220.

With additional reference to FIG. 3, the process 100 may include amodeling procedure 110, which generally involves generating one or moremodels using the modeling device 210. The illustrated modeling device210 includes a display device 212, a user input device 214, and acomputing device 219 operably connected with the display device 212 andthe user input device 214. The computing device 219 includes modelingtools 218, which enable the user to generate the models, viewinformation relating to the models on the display device 212, andmanipulate the models using the user input device 214. Further detailsregarding an exemplary form of the computing device 219 is providedbelow with reference to FIG. 17.

The modeling procedure 110 includes an operation 112, which involvesgenerating a porous structure model 121 having the initial porositycharacteristic 107. The operation 112 may, for example, includegenerating a unit cell 310 including a plurality of struts 312, whichgenerally define a plurality of faces 314 and a pore 319 of the unitcell 310. While the unit cell 310 is illustrated as a cubical unit cell,it is also contemplated that the unit cell 310 may be provided inanother form of space-filling polyhedron, such as an icosahedron or adodecahedron. The operation 112 may include selecting a size for unitcell 310 and one or more thicknesses for the struts 312 based upon theinitial porosity characteristic 107. The operation 112 may furtherinclude generating the porous structure model 121 by instancing the unitcell 310 to create a lattice in which adjacent cells share a face 314and the pores 319 are interconnected. As will be appreciated, the degreeof interconnection between pores of adjacent unit cells depends upon anumber of factors, such as the size of the pores 319 and the thicknessof the struts 312.

In the illustrated form, the porous structure model 121 is defined by aregular lattice comprising a plurality of identical unit cells 310, suchthat the pore 319 of each cell 310 has a pore size corresponding to theinitial pore size 107 a, and the ratio of the total volume of the pores319 to the total volume of the model 121 corresponds to the porosityfraction 107 c. It is also contemplated that unit cells 310 may betessellated in another manner and/or at least partially or fullyrandomized to form the model, and that the cells vary in size and/orgeometry. For example, the size of the pores 319 may vary within thetarget range 107 b, such that the model 121 has the initial average poresize 107 a and the initial porosity fraction 107 c. In certainembodiments, the operation 112 may involve generating the model 121 suchthat when a porous structure built according to the model 121 issubjected to the forging procedure 140, the resulting deformed layer 346has the target porosity characteristic 103.

The procedure 110 may further include one or more additional operations113-117, each of which may involve generating an additional model to beutilized in a corresponding one of the procedures 130-170. For example,an operation 113 may involve generating a heat treatment model 131 to beutilized in the heat treatment procedure 130, an operation 114 mayinvolve generating a forging model 141 to be utilized in the forgingprocedure 140, and an operation 115 may involve generating a moldingmodel 151 to be utilized in the molding procedure 150. Similarly, anoperation 116 may involve generating a machining model 161 to beutilized in the machining procedure 160, and an operation 117 mayinvolve generating a finishing model 171 to be utilized in the finishingprocedure 170. In certain embodiments, one or more of the models mayhave been previously generated or may be unnecessary, and thecorresponding operations may be omitted accordingly.

With additional reference to FIGS. 4 and 5, the additive manufacturingprocedure 120 generally involves manufacturing a porous structure orinitial part 320 using the additive manufacturing device 220. In theillustrated form, the additive manufacturing device 220 generallyincludes a housing 221, a build plate 222 movably mounted to the housing221, a bed of raw material 223 supported by the build plate 222, a beamscanner 224 operable to generate a beam 225, and a controller 229 incommunication with the beam scanner 224. The controller 229 may furtherbe in communication with an actuator 228 operable to move the buildplate 222 and/or a material distributor 226 operable to distribute rawmaterial 223. In certain embodiments, the controller 229 may be incommunication with the network and/or controlled by the control system290.

In certain forms, the additive manufacturing procedure 120 may beprovided as a selective laser sintering (SLS) procedure, in which thebeam 225 is provided in the form of a laser and the raw material 223 isprovided in a powdered form. By way of example, the powdered rawmaterial 223 may include stainless steel and/or one or more alloys, suchas titanium alloys, zirconium alloys, and cobalt-chromium alloys. Inother embodiments, other forms of additive manufacturing techniques maybe utilized in the additive manufacturing procedure 120, such as thosein which the beam 225 is provided in the form of an electron beam and/orthe raw material 223 is provided as a liquid.

The additive manufacturing procedure 120 includes an operation 122,which includes receiving the porous structure model 121 at the additivemanufacturing device 220, and building the porous structure 320according to the model 121. During the operation 122, the beam scanner224 generates a beam 225 which causes portions of the raw material 223contacted by the beam 225 to transition states, thereby forming an addedmaterial layer 227 to the part 320. In the illustrated form, the rawmaterial 223 that is melted by the beam 225 to generate a melt pool,which solidifies to form a portion of the added material layer 227. Thecontroller 229 may control the generation and direction of the beam 225such that the added material layer 227 is formed according to acorresponding layer in the model 121.

After each added material layer 227 is formed on the part 320, the buildplate 222 is lowered by a distance corresponding to the thickness of theadded material layer 227. For example, the controller 229 may operate anactuator 228 such as a motor or hydraulic device to lower the buildplate 222 by the appropriate amount. With the build plate 222 lowered,the recently added layer 227 is covered by raw material 223. Forexample, the controller 229 may issue a command which causes thematerial distributor 226 to distribute additional raw material 223 overthe previously-added material layer 227. The steps are then repeated toform additional added material layers 227 according to the model 121until the porous structure 320 is complete.

The procedure 120 may further include an operation 124, which involvesrelieving the initial part 320 of stresses generated during the buildingoperation 122. The operation 124 may, for example, include utilizing astress-relief annealing technique while the part 320 is still mounted tothe build plate 222. The procedure 120 further includes an operation126, which involves removing the part 320 from the build plate 222. Theoperation 126 may further include cleaning the part 320 to remove excessraw material 223 from the part 320, for example using conventional wetand/or dry cleaning techniques.

As illustrated in FIG. 5, the initial part 320 includes at least oneporous portion 322, 324 having a plurality of original or initial pores329. At least one of the porous portions 322, 324 has the initialporosity characteristic 107 selected in the operation 106. For example,the initial porosity characteristic 107 may include an initial averagepore size 107 a, and the pores 329 in at least one of the porousportions 322, 324 may have an average pore size corresponding to theinitial average pore size 107 a. In certain embodiments, the initialporosity characteristic 107 may include a range 107 b of initial poresizes, and the pores 329 may have sizes defined by the range 107 b.Additionally or alternatively, the initial porosity characteristic 107may include an initial porosity fraction 107 c, and the pores 329 mayprovide at least one of the portions 322, 324 with the selected initialporosity fraction 107 c. As illustrated in the inset of FIG. 5a , theinitial pores 329 exhibit a relatively high level of interconnectionwith one another.

As noted above, selection of the initial porosity characteristic 107 mayaffect and be affected by the operating parameters associated with theadditive manufacturing procedure 120. For example, laser-based additivemanufacturing techniques can typically produce much finer pores comparedto those techniques which utilize an electron beam. However, bothtechniques have difficulty in producing interconnecting pores that aresmaller than a threshold pore size. The threshold pore size depends onthe operating parameters associated with the particular additivemanufacturing technique being utilized, such as the powder size of theraw material 223 and the size of the melt pool generated by the beam225. For example, the powder size may be in the range of 40 microns to100 microns, and the melt pool diameter may be in the range of 25microns to 100 microns, depending on beam power, spot size, and scanspeed. In such forms, it may be challenging to create initial pores 329having a size less than a threshold pore size of about 100 microns.

Additionally, the computing and printing time can be significantlylarger for structures with smaller pores than those with larger pores.In certain embodiments, the operation 106 may include selecting theinitial porosity characteristic 107 based at least in part upon criteria105 relating to the particular techniques and/or operating parameters tobe utilized in the additive manufacturing procedure 120. For example,such criteria 105 may relate to one or more of the average powder sizefor the raw material 223, the type of beam 225 utilized, the diameter ofthe melt pool generated by the beam 225, the computing time needed togenerate the model 121, and the printing time needed to build the porousstructure 320. Additionally or alternatively, a criterion 105 may relateto a threshold pore size, which may be based at least in part upon thepowder size associated with the raw material 223 and/or the size of themelt pool generated by the beam 225.

With additional reference to FIG. 6, the process 100 may further includethe heat treatment procedure 130, which generally involves utilizing theheat treatment device 230 to heat treat the porous structure 320. In theillustrated form, the heat treatment device 230 is provided in the formof an oven or high-temperature furnace 230 having a chamber 232 operableto receive the initial part 320, a heating element 234 operable to heatthe part 320, and a controller 239 in communication with the heatingelement 234. The oven 230 may further include one or more pumps 235configured to control the flow of a gas 236 or vacuum pressure intoand/or out of the chamber 232, and the controller 239 may be incommunication with the pumps 235.

The heat treatment procedure 130 includes an operation 132, whichincludes receiving the heat treatment model 131 at the heat treatmentdevice 230, and heat treating the porous structure 320 according to themodel 131. In certain embodiments, the heat treatment model 131 mayinclude a temperature profile 133 defining one or more of a heatingrate, a target temperature, a time associated with the targettemperature, and a cooling rate. In such forms, the operation 132 mayinclude controlling the heating element 234 such that the temperaturewithin the chamber 232 increases to the target temperature at theheating rate, maintains the target temperature for the predeterminedamount of time, and decreases from the target temperature at the coolingrate. In certain embodiments, the heat treatment model 131 may furtherinclude a gas flow model 135, and the operation 132 may includecontrolling the pumps 235 to control the inflow and/or outflow of thegas 236 according to the gas flow model 135.

With additional reference to FIGS. 7 and 8, the forging procedure 140generally involves utilizing the forging device 240 to form a forgedpart 340 from the initial part 320. In the illustrated form, the forgingdevice 240 generally includes an anvil 242 having a securing device 243,a hammer 244 having a striker 245, and a controller 249 in communicationwith the hammer 244. The forging device 240 may further include aheating element 247, and the controller 249 may be in communication withthe heating element 247. The forging procedure 140 includes an operation142, which generally includes placing the porous structure 320 on theanvil 242, and which may further include securing the porous structure320 to the anvil 243 using the securing device 243. While the securingdevice 243 is illustrated as a clamp, it is also contemplated that otherforms of securing device may be utilized.

The forging procedure 140 also includes an operation 144, which includesreceiving the forging model 141 at the controller 249, and operating theforging device 240 according to the model 141. For example, the forgingmodel 141 may include location information 143 indicating locations atwhich the part 320 is to be struck, and striking information 145indicating the number of times the striker 245 is to strike the part 320at each location and the force with which each strike is to bedelivered. In such forms, the operation 144 may include operating thehammer 244 to cause the striker 245 to strike the part 320 according tothe striking information 145 in the locations indicated by the locationinformation 143.

In certain embodiments, the forging model 141 may include heatinginformation 147, and the operation 144 may include operating the heatingelement 247 according to the heating information 147. For example, theoperation 144 may include operating the heating element 247 to bring thepart 320 to a temperature indicated by the heating information 147 priorto operating the hammer 244 according to the striking information 145.In certain embodiments, the operation 144 may include operating theheating element 247 to maintain the part 320 at the desired temperaturefor at least a portion of the duration of the forging.

With the operation 144 complete, at least one porous portion 324 of theinitial part 320 has been converted to a forged region 344, and theinitial part 320 has been converted to a forged part 340. The procedure140 may then continue to an operation 146, which involves removing theforged part 340 from the anvil 242. In certain embodiments, one or moreheat treatments may be performed on the forged part 340, such assintering and/or hipping.

As a result of the forging procedure 140, at least a portion of theporous structure 320 has been deformed, such that the forged part 340includes a forged region 344. For example, the forged part 340illustrated in FIG. 8 includes an unforged first region 342corresponding to the first porous portion 322, and a forged secondregion 344 corresponding to the second porous portion 324. Additionally,the unforged first region 342 has a first thickness 343 corresponding tothe thickness 323 of the first porous portion 322, and the forged secondregion 344 has a second thickness 345 less than the thickness 325 of thesecond porous portion 324. The thickness 345 of the forged second region344 may, for example, be in the range of 50% to 80% of the thickness 325of the second portion 324 of the initial part 320.

Due to the fact that the unforged region 342 has not been struck, theunforged region 342 maintains the general configuration of thecorresponding first portion 322 of the initial porous structure 320. Asa result, the unforged region 342 includes the original or initial pores329, and has the initial porosity characteristic 107. In contrast, atleast some of the pores in the forged region 344 have been converted tomodified pores 349, such that at least a portion of the forged region344 has the target porosity characteristic 103. More specifically, theforged region 344 includes a deformed layer 346 formed adjacent thesurface struck by the striker 245 during the forging procedure 140, andthe deformed layer 346 has the target porosity characteristic 103. It isinteresting to note that when a solid structure is subjected to forging,deformation typically occurs throughout the thickness of the forgedregion. However, it has been found that when a porous structure such asthe initial part 320 is subjected to forging, the forged region 344 mayretain an undeformed layer 347 below the deformed layer 346.

The retention of such an undeformed layer 347 may depend upon a numberof factors, such as the porosity of the porous portion 324 and thereduction in thickness imparted by the forging procedure 140. Thus,layers having varying porosity characteristics can be formed from auniform porous structure, for example by appropriately selecting theinitial porosity characteristic 107 and the forging model 141.Unexpectedly, it has been found that the process of forging a porousstructure in this manner may be more easily and efficiently tailored toprovide desired porosity characteristics than would be feasible bysimply adjusting the operating parameters associated with the additivemanufacturing procedure 120. As one example, the deformed layer 346 maybe provided with pores 349 having a smaller size than would normally befeasible to produce using the additive manufacturing procedure 120alone. For example, when the additive manufacturing procedure 120 has athreshold pore size corresponding to the powder size and/or melt pooldiameter, the operation 102 may include selecting the target averagepore size 103 a less than the threshold pore size, and the operation 106may include selecting the initial average pore size 107 a greater thanthe threshold pore size.

The deformation of the material in the forged region 344 not onlyreduces the average size of the modified pores 349, but also reduces thelevel of interconnection between the modified pores 349. Thus, while theunforged region 342 retains the initial porosity characteristics 107(i.e., a larger average pore size and/or higher porosity) such that theoriginal pores 329 remain highly interconnected (FIG. 8a ), the deformedlayer 346 of the forged region 344 has the target porositycharacteristics 103 (i.e., a smaller average pore size and/or lowerporosity) such that the modified pores 349 are less interconnected(FIGS. 8b and 9). Like the unforged region 342, the undeformed layer 347also retains the initial porosity characteristics 107, such that thepores 329 thereof remain highly interconnected (FIGS. 8b and 9).

While the layer 347 is described above as an undeformed layer whichretains the initial porosity characteristic 107, it is to be understoodthat the layer 347 may be slightly deformed during the forging procedure140. Accordingly, the layer 347 may alternatively be provided as asubstantially undeformed layer which substantially retains initialporosity characteristic 107. Such a substantially undeformed layer 347may have an average pore size which is slightly smaller than the initialpore size 107 a. By way of example, the forging procedure 140 may imparta reduction in average pore size in the range of 10% to 20%, such thatthe average pore size of the substantially undeformed layer is 80% to90% of the initial pore size. For purposes of illustration, FIG. 9illustrates the deformed and undeformed layers 346, 347 as discrete andadjacent layers having the target and initial porosity characteristics103, 107, respectively. It is to be understood, however, that there maybe a gradient in the porosity characteristic, and that a transitionallayer may be formed between the deformed layer 346 and the undeformedlayer 347.

In the illustrated form, only the second portion 324 of the initial part320 has been subjected to forging in the forging procedure 140, suchthat the first region 342 of the forged part 340 is an unforged region.It is also contemplated that the first portion 322 of the initial part320 may be subjected to forging, such that the first region 342 of theforged part 340 is also a forged region. In certain embodiments, boththe first and second portions 322, 324 of the initial part 320 may beforged according to the same striking information 145, such that thefirst and second regions 342, 344 of the forged part 340 aresubstantially similar. In other embodiments, the forging model 141 mayindicate that one portion of the initial part 320 is to be forged to agreater degree than another portion of the part 320, such as byindicating that the first portion 322 is to be struck a fewer number oftimes and/or with a lower force than the second portion 324. Forexample, the forging model 141 may be provided such that after theforging procedure 140, the deformed layer 346 of the second region 344has the target porosity characteristics 103, and the first region 342includes a deformed layer having the additional target porositycharacteristics 103′. In further embodiments, the forging procedure 340may further include striking the opposite side of the second porousportion 324, thereby forming an additional deformed layer.

While the illustrated forging procedure 140 utilizes an open-die forgingtechnique, it is to be appreciated that additional and/or alternativetechniques may be utilized to form the deformed layer 346. By way ofexample, the forging procedure 140 may additionally or alternativelyutilize a closed-die forging technique and/or an alternative techniquewhich produces deformations by a process other than forging. In certainembodiments, such alternative techniques may include rolling and/or deepdrawing the initial part 320.

In certain embodiments, the forged part 340 may be utilized as theworkpiece 163 which is machined in the machining operation 160, forexample in embodiments in which bulk material removal is required tobring the forged part 340 into the general form of an orthopedic device.In other embodiments, the forged part 340 may be utilized as theunfinished orthopedic device 173 which is finished in the finishingprocedure 170, for example in embodiments in which the forged part 340has the general configuration of the orthopedic device 370 and bulkmaterial removal is not necessary. In certain embodiments, the forgedpart 340 may be bonded to a metallic substrate, such as by usingsintering or diffusion bonding processes, and the resulting part may beutilized as the workpiece 163 or unfinished orthopedic device 173. Infurther embodiments, the resulting part or the forged part 340 alone maybe utilized in the molding procedure 150, further details of which willnow be provided.

With additional reference to FIGS. 10 and 11, certain embodiments of theprocess 100 may include the molding procedure 150, which generallyinvolves utilizing the molding device 250 to form a molded part 350 fromthe forged part 340. The molding device 250 generally includes a mold252 having an internal cavity 253, which is configured to provide apolymeric composition 255 received in the mold 252 with a configurationcorresponding to a desired geometry of the polymeric portion 375 of theorthopedic device 370. In the illustrated form, the polymericcomposition is provided in the form of a liquid 255 stored in areservoir 256, and the molding device 250 includes an injection device254 operable to inject the liquid 255 into the cavity 253 under thecontrol of a controller 259. The liquid 255 is one form of a polymericcomposition which, when solidified, is suitable to provide an articularor non-articular smooth surface 376 for the orthopedic device 370. Byway of example, such a polymeric composition may include a polyethylenecompound, such as an ultra-high molecular weight polyethylene orpolyether ether ketone (PEEK). The molding device 250 may furtherinclude a curing device 257 operable to solidify the liquid 255 or otherform of polymeric composition, and the controller 259 may be incommunication with the curing device 257. While the illustrated moldingdevice 250 is provided in the form of an injection molding device, it isalso contemplated that the molding device 250 may be provided in anotherform, such as a compression molding device. An example of such acompression molding device 590 is described below with reference to FIG.15.

The molding procedure 150 includes an operation 152, which generallyinvolves placing at least a portion of the forged part 340 in the mold252 such that the forged region 344 is received within the cavity 253,and such that the deformed layer 346 faces the cavity 253. The procedure150 further includes an operation 154, which generally involvesinfiltrating a polymeric composition into the pores 349 of the deformedlayer 346. In the illustrated form, the operation 154 includes injectingthe liquid polymeric composition 255 into the cavity 253 such that theliquid polymeric composition 255 infiltrates the deformed layer 347 ofthe forged region 344. The operation 154 may include receiving themolding model 151 at the controller 259, and operating the injectiondevice 254 to inject the liquid 255 according to the model 151. Forexample, the molding model 151 may include an injection model 153indicating the amount of liquid polymeric composition 255 to be injectedinto the cavity 253 and/or an operating pressure sufficient to result inthe desired degree of infiltration.

The molding procedure 150 further includes an operation 156, whichgenerally involves solidifying the liquid polymeric composition 255 toform an attached part 355, such that the molded part 350 includes theforged part 340 and the attached part 355. Due to the fact that at leastsome of the pores 349 of the deformed layer 346 were infiltrated by theliquid 255 in the operation 154, the operation 156 results in theformation of an infiltrated layer 356 by which the attached part 355 issecurely fixed to the forged part 340. More specifically, theinfiltrated layer 356 includes infiltrated pores 359 in which portionsof attached part 355 are formed, such that the attached part 355 ispartially formed within the infiltrated layer 356. While the pores 359in the infiltrated layer 356 have been filled with the solidifiedliquid, the size and shape of the pores 359 does not materially change.Accordingly, the deformed layer 346 may be considered to retain thetarget porosity characteristic 103.

In certain embodiments, the molding model 151 may include a curing model157, and the operation 156 may include solidifying the liquid polymericcomposition 255 by operating the curing device 257 according to thecuring model 157. In other embodiments, the operation 156 may notnecessarily involve operating the curing device 257, and may insteadinvolve allowing the liquid 255 to solidify by cooling. With theoperation 156 complete and the molded part 350 formed, the procedure 150may continue to an operation 158, which generally involves removing themolded part 350 from the mold 252.

In the illustrated form, the operation 154 includes operating themolding device 250 such that the liquid polymeric composition 255 doesnot infiltrate the entire depth of the deformed layer 346. Thus, whenthe liquid 255 is solidified in the operation 156, the infiltrated layer356 does not extend into the undeformed layer 347 (FIG. 11).Accordingly, the undeformed layer 347 may remain highly porous, whichmay be desirable to promote tissue in-growth. Due to the fact that thedeformed layer 346 has the smaller average pore size and/or lowerporosity defined by the target porosity characteristics 103,infiltration of the liquid polymeric composition 255 into the deformedlayer 346 in the operation 154 may be more closely controlled than wouldbe feasible if the deformed layer 346 were to have the larger averagepore size and/or higher porosity defined by the initial porositycharacteristics 107. In other words, the target porosity characteristics103 provided to the deformed layer 346 may aid in controlling the depthto which the liquid 255 infiltrates the forged region 344.

In certain embodiments, the molded part 350 may be utilized as theunfinished orthopedic device 173 that is finished in the finishingprocedure 170. For example, the manufacturing procedure 120 and/orforging procedure 140 may result in the forged part 340 having ageometry suitable for the body portion 371 of the orthopedic device 370,and the molding procedure 150 may result in the attached part 355 beingsubstantially in the form of the articular portion 375 of the orthopedicdevice 370. In certain forms, the operation 115 may involve generatingthe molding model 151 based at least in part upon the desired finalconfiguration of the articular portion 375, and the mold cavity 253 maybe formed based upon such a molding model 151, such that the attachedpart 355 defines the articular portion 375. In other embodiments, themolded part 350 may be utilized as the workpiece 163 which is machinedin the machining procedure 160, further details of which will now beprovided.

With additional reference to FIG. 12, the process 100 may furtherinclude the machining procedure 160, which generally involves utilizingthe machining device 260 to form a machined part 360 from a workpiece163, such as the forged part 340 or the molded part 350. The process 100may include the machining procedure 160 when bulk material removal isneeded to bring the forged part 340 or molded part 350 into the generalform desired for the orthopedic device 370. The machining device 260generally includes a holder 262, a mill 264 including a cutting bit 265,and a controller 269 which controls operation of the mill 264. Themachining device 260 may further include at least one driver 267operable to move the holder 262 and/or the mill 264 in response tocommands from the controller 269. For example, the machining device 260may be a Computer Numerical Control (CNC) machining device, and thecontroller 269 may control the mill 264 and/or the driver 267 to machinethe workpiece 163 according to the machining model 161.

The machining procedure 160 may begin with an operation 162, whichgenerally involves securing the workpiece 163 to the holder 262. Theprocedure 160 may then continue to an operation 164, which generallyinvolves receiving the machining model 161 at the controller 269, andmachining the workpiece 163 according to the model 161. Morespecifically, the operation 164 includes removing bulk material from theworkpiece 163 such that the machined part 360 has the general formdesired for the orthopedic device 370. In certain embodiments, theworkpiece 163 may include the forged part 340, and the operation 164 mayinclude machining the forged part 340 into a form suitable to serve asthe body portion 371 of the orthopedic device 370. In certainembodiments, the workpiece 163 may be provided in the form of the moldedpart 350, and the operation 164 may include machining the attached part355 into a form suitable to serve as the articular surface 376 of theorthopedic device 370. With the operation 164 complete, the procedure160 may continue to an operation 166, which involves removing themachined part 360 from the holder 262. In certain embodiments, themachined part 360 may be utilized as the unfinished orthopedic device173 that is finished in the finishing operation 170, further details ofwhich will now be provided.

The finishing procedure 170 generally involves utilizing the finishingdevice 270 to form a finished orthopedic device 370 from an unfinishedorthopedic device 173. As noted above, the unfinished orthopedic device173 may be provided as the forged part 340, the molded part 350, or themachined part 360. For example, in embodiments in which the forged part340 is substantially in the form of the body 371 of the orthopedicdevice 370, the bulk material removal provided in the machiningprocedure 160 may be unnecessary, and the forged part 340 may serve asthe unfinished orthopedic device 173. As another example, in embodimentsin which the molded part 350 is in the general form of the orthopedicdevice 370 (e.g., the forged part 340 is substantially in the form ofthe body 371 and the attached part 355 is substantially in the form ofthe articular portion 375), the molded part 350 may serve as theunfinished orthopedic device 173. As a further example, in embodimentsin which the bulk material removal provided by the machining procedure160 is needed to bring the forged part 340 to the general form of thebody 371 and/or to bring the attached part 355 to the general form ofthe articular surface portion 375, the machined part 360 may serve asthe unfinished orthopedic device 173.

The finishing procedure 170 includes an operation 172, which generallyinvolves receiving the finishing model 171 at the finishing device 270,and finishing the unfinished orthopedic device 173 according to themodel 171. When the unfinished device 173 is substantially in thedesired form for the finished device 370, the operation 172 may includeperforming fine material removal in order to bring the unfinished device173 to the final form desired for the finished device 370. By way ofexample, such fine material removal may be performed to bring thearticular surface 376 to a desired smoothness. In certain embodiments,the operation 172 may include treating one or more surfaces of theunfinished device 173. For example, in embodiments in which theorthopedic device 370 includes a porous tissue-facing region 372intended to foster tissue in-growth, the model 171 may indicate that theoperation 172 is to include treating the porous tissue-facing region 372with a coating which promotes such tissue in-growth. As another example,the operation 172 may include plasma spraying the device 173, such aswith hydroxyapatite. In certain embodiments, the operation 172 mayinclude cleaning the unfinished device 173 to remove loose particles.

The procedure 170 may further include an operation 174, which generallyinvolves packaging and sterilizing the finished device 370 to form apackaged unit 380. For example, the model 171 may include packaging andsterilization models, and the operation 174 may include operating thefinishing device 270 to package and sterilize the finished orthopedicdevice 370 according to the model 171. The packaged unit 380 may then beready for shipment and/or use.

FIG. 14 illustrates an orthopedic device in the form of an acetabularcup 400 that may be created using certain embodiments of the process 100and system 200. With continued reference to FIGS. 1-13, one exemplaryimplementation of the process 100 will now be described in connectionwith the acetabular cup 400 illustrated in FIG. 14. It is to beunderstood, however, that the implementation described hereinafter maybe utilized to create other forms of orthopedic implants havingpolymeric portions, which may define an articular surface and/or anon-articular surface. By way of example, such a polymeric portion maydefine a non-articular surface structured to discourage attachment ofsoft tissue, such as muscle, tendons, and/or ligaments.

The acetabular cup 400 is an embodiment of the finished orthopedicdevice 370, and includes certain features which correspond to thosedescribed above in connection with the manufacturing stages illustratedin FIGS. 3-13. Unless indicated otherwise, similar reference charactersare used to indicate similar elements and features. For example, theacetabular cup 400 includes a body portion 471 formed of a forged part440 and an articular portion 475 formed of an attached part 455, whichrespectively correspond to the body portion 371, forged part 350,articular portion 375, and attached part 355 described above. In theinterest of conciseness, the following description focuses primarily onfeatures of the acetabular cup 400 and the instant implementation of theprocess 100 which may not necessarily have been described above withreference to the manufactured product 300 and the process 100.

In the instant embodiment, the body portion 471 formed of the forgedpart 440 includes an inward-facing fixation region 474 and atissue-facing in-growth region 472. More specifically, the fixationregion 474 is formed of the deformed layer 446, and the in-growth region472 is formed of the second layer 447. The in-growth region 472 definesa bone-facing surface of the cup 400, and is structured to promotetissue in-growth when the cup 400 is implanted into the acetabularsocket of a patient. Additionally, the fixation region 474 includes aninfiltrated layer 456, through which the attached part 455 that definesthe articular portion 475 is affixed to the body portion 471.

In the instant embodiment, the operation 102 includes selecting thetarget porosity characteristic 103 for the fixation region 474 based atleast in part upon a criterion 101 relating to the molding procedure150. For example, the criteria 101 may relate to one or more of thecomposition of the liquid 255, a desired infiltration of the liquid 255into the deformed layer 346, and a desired degree of control over theinfiltration. The operation 102 may include selecting the targetporosity characteristic 103 to provide the desired infiltration and/orcontrol thereof based at least in part upon the composition and/orviscosity of the liquid 255. For example, the operation 102 may includeselecting the target porosity characteristic 103 with a target averagepore size 103 a and/or a target porosity fraction 103 c sufficient toensure that the liquid 255 does not permeate through the deformed layer346, 446 and into the undeformed layer 347, 447. By way of example, thetarget porosity characteristic 103 may include a target average poresize 103 a of less than 500 microns and/or a target porosity fraction103 c in the range of 15% to 35%.

In the instant embodiment, the in-growth region 472 corresponds to theundeformed layer 347 illustrated in FIG. 11, such that the in-growthregion 472 has the initial porosity characteristic 107. Accordingly, theoperation 106 includes selecting the initial porosity characteristic 107based at least in part upon a criterion 105 relating to desiredin-growth characteristics for the in-growth region 472. The selection ofthe initial porosity characteristic 107 may be further based upon atleast one additional criterion 105, such as a criterion relating todesired load-bearing characteristics for the in-growth region 472. Byway of example, the initial porosity characteristic 107 may include anaverage pore size 107 a and/or porosity fraction 107 c selected topromote tissue in-growth while providing the desired load bearingcharacteristics, such as an initial average pore size 107 a of less than1000 microns and/or a porosity fraction 107 c in the range of 35% to70%. The initial porosity characteristic 107 may additionally oralternatively include an initial pore size range 107 b, such as a range107 b having a lower limit between 100 microns and 300 microns and anupper limit between 500 microns and 1000 microns.

In the modeling procedure 110, the operation 112 involves generating theporous structure model 121 with the initial porosity characteristic 107.The operation 112 may involve generating the porous structure model 121based at least in part upon the desired final configuration of the bodyportion 471 of the acetabular cup 400. For example, the porous structuremodel 121 may have the overall configuration of the body portion 471 anda slightly greater thickness than the body portion 471, such that whenthe porous structure 320 is subjected to the forging procedure 140, theforged part 440 defines the body portion 471.

In the additive manufacturing procedure 120, the initial part 320 isformed according to the model 121 using a selective laser sinteringadditive manufacturing technique, and stresses are relieved while theinitial part 320 is attached to the build plate 222. After being formedin the additive manufacturing procedure 120, the porous structure 320 isheat treated in the heat treatment procedure 130. While other times andtemperatures may be utilized, in the instant embodiment, the heattreatment procedure 130 involves heating the porous structure 320 in airat 650° C. for 30 minutes.

In the forging procedure 140, the initial part 320 is heated to adesired temperature, and is struck according to the forging model 141 toform the forged part 340. In the instant embodiment, the forgingprocedure 140 involves striking the inner side of the initial part 320such that the thickness 345 of the forged region 344 is between 50% and80% of the thickness 325 of the corresponding porous portion 324 of theoriginal part 320. As a result of the forging, the tissue-facing region472 is defined by the undeformed layer 347, 447, and the fixation region474 is defined by the deformed layer 346, 446. Accordingly, thetissue-facing region 472 has the initial porosity characteristic 107selected based at least in part upon a criterion 105 related to tissuein-growth, and the fixation region 474 has the target porositycharacteristic 103 selected based at least in part upon the infiltrationof the liquid 255.

It is also contemplated that the forging procedure 140 may involvestriking the outer side of the porous structure 320 to form a seconddeformed layer that defines the in-growth region 472. In suchembodiments, the operation 102 may involve selecting an additionaltarget porosity characteristic 103′ for the first porous region 472based at least in part upon a criterion 101 relating to bone in-growth,and the operation 106 may involve selecting the initial porositycharacteristic 107 based at least in part upon a criterion 105 relatingto the additional target porosity characteristic 103′. By way ofexample, the additional target porosity characteristic 103′ may includea target average pore size in the range of 100 microns to 300 microns,and the initial porosity characteristic 107 may include an initialaverage pore size of greater than 500 microns.

With additional reference to FIG. 15, illustrated therein is acompression molding device 490 that may be utilized in certain forms ofthe molding procedure 150. The molding device 490 includes a mold 492including first and second sections 492 a, 492 b, each of which includesa surface 493 a, 493 b that partially defines a cavity 493 of the mold492. More specifically, the first section 492 a has a first innersurface 493 a which generally conforms to the outer surface of theforged part 440, and the second section 492 b has a second inner surface493 b which generally conforms to the desired configuration of thearticular surface 476. In the instant embodiment, the molding procedure150 involves placing a polymeric composition 495 in the second moldsection 492 b such that the polymeric composition 495 generally conformsto the second inner surface 493 b. With the forged part 440 seated inthe first mold section 492 a, an actuator 494 such as a hydraulic pistonis actuated to drive first and second sections 492 a, 492 b toward oneanother, thereby causing the composition 495 to infiltrate the deformedlayer 446. The composition 495 is then solidified, thereby creating theattached part 455 which defines the articular portion 475.

In certain forms, the polymeric composition 495 may be provided in theform of a partially solidified shaped charge, and the molding procedure150 may involve solidifying the composition 495 after the deformed layer446 is infiltrated. In other embodiments, the polymeric composition 495may be provided in the form of a powder, and the procedure 150 mayinvolve activating a heating element 497 to at least partially melt thecomposition 495, for example as the mold sections 492 a, 492 b are beingdriven together. In the event that flash is generated as a result of thecompression molding, such flash may be removed in the machiningprocedure 160 and/or the finishing procedure 170.

With the forged part 440 defining the cup body portion 471 and theattached part 455 defining the articular portion 475, the molded part350 may be substantially in the form of the finished acetabular cup 400.In such forms, the bulk material removal provided by the machiningprocedure 160 may be unnecessary, and the process 100 may continue tothe finishing procedure 170 using the molded part 350 as the unfinishedorthopedic device 173. In the event that bulk material removal isrequired, the molded part 350 may be utilized as the workpiece 163 inthe machining procedure 160, and the machined part 360 may be utilizedas the unfinished orthopedic device 173 in the finishing procedure 170.

With an unfinished orthopedic device 173 prepared, the process 100 maycontinue to the finishing procedure 170. In the finishing procedure 170,the operation 172 may include surface treating the first porous region472 and/or the articular portion 475, for example to provide the treatedcomponents with desired wear and/or hardness characteristics. Theoperation 172 may additionally or alternatively include treating thefirst porous region 472 with a compound that promotes tissue in-growth.The finishing procedure 170 may further include packaging and/orsterilizing the acetabular cup 400, for example as described above.

FIG. 16 illustrates an orthopedic device in the form of a femoralimplant 500 that may be created using certain embodiments of the process100 and system 200. With continued reference to FIGS. 1-13, anotherexemplary implementation of the process 100 will now be described inconnection with the femoral implant 500 illustrated in FIG. 16. It is tobe understood, however, that the implementation described hereinaftermay be utilized to create other forms of orthopedic devices andinstruments, such as tibial or patellar implants.

The femoral implant 500 is an embodiment of the finished orthopedicdevice 370, and includes certain features that correspond to thosedescribed above in connection with the manufacturing stages illustratedin FIGS. 3-13. Unless indicated otherwise, similar reference charactersare used to indicate similar elements and features. For example, thefemoral implant 500 includes a body portion 571 formed of a forged part540 having a deformed layer 546 defining an in-growth region 576, whichrespectively correspond to the body portion 371, forged part 340,deformed layer 346, and tissue-facing region 376 described above. In theinterest of conciseness, the following description focuses primarily onfeatures of the femoral implant 500 and the instant implementation ofthe process 100 that may not necessarily have been described above withreference to the manufactured product 300 and the process 100.

The operation 102 involves selecting the target porosity characteristic103 based at least in part upon a criterion 101 relating to desiredin-growth characteristics for the in-growth region 576. The selection ofthe target porosity characteristic 103 may be further based upon atleast one additional criterion 101, such as a criterion relating todesired load-bearing characteristics for the in-growth region 576. Byway of example, the target porosity characteristic 103 may include anaverage pore size and/or porosity selected to promote tissue in-growthwhile providing the desired load bearing characteristics, such as aninitial average pore size 107 a of less than 1000 microns and/or aporosity fraction 107 c in the range of 35% to 70%. The target porositycharacteristic 103 may additionally or alternatively include an initialpore size range 103 b, such as a range 103 b having a lower limitbetween 100 microns and 300 microns and an upper limit between 500microns and 1000 microns.

The operation 106 involves selecting an initial porosity characteristic107 greater than the target porosity characteristic 103. Morespecifically, the operation 106 involves selecting the initial porositycharacteristic based at least in part upon a criterion 105 relating toat least one of the modeling procedure 110 and the additivemanufacturing procedure 120. By way of example, the criterion 105 mayrelate to computing time associated with the generation of the porousstructure model 121 in the operation 112 and/or build time associatedwith manufacturing the initial part 320 in the operation 122, and theoperation 106 may involve selecting the initial porosity characteristic107 to reduce or optimize the computing time and/or build time. Theinitial porosity characteristic 107 may include one or more of a targetaverage pore size 107 a greater than 1000 microns, a pore size range 107b having a minimum pore size in the range of 800 microns to 1200microns, and/or a porosity fraction 107 c in the range of 50% to 85%. Inthe instant implementation, the initial porosity characteristic 107includes a pore size range 107 b having a minimum pore size greater thanthat which is desired for tissue in-growth, such as a minimum pore sizeof 1000 microns.

In the additive manufacturing procedure 120, the initial part 320 ismanufactured with a porous portion 524 having initial pores 329 largerthan the minimum pore size of 1000 microns. The initial part 320 is thenforged in the forging procedure 140, thereby forming the in-growthregion 576 with the target porosity characteristic 103. In certainembodiments, the forging procedure 140 may include striking the porousportion 324, 524 such that the sizes of at least a predeterminedpercentage of the pores in the in-growth region 576 are less than theupper limit of the target range 103 b. By way of example, the forgingprocedure 140 may result in at least 90% of the pores in the in-growthregion 576 having a pore size less than an upper limit of 1000 microns.The forged part 540 may then be subjected to the machining procedure 160and/or the finishing procedure 170 to produce the finished femoralimplant 500.

In the illustrated embodiment, the articular portion 572 of the femoralimplant is formed during the additive manufacturing procedure 120, suchthat the articular portion 572 is included in the initial part 320. Inother embodiments, the articular portion 572 may not necessarily beincluded in the initial part 320. As one example, the articular portion572 may be formed by infiltrating a forged part with a polymericcomposition, for example as described above with reference to FIGS. 10and 11 and/or FIG. 14. In other embodiments, the articular portion 572may be a metal part formed according to known techniques. In such forms,the forged part 540 may define the in-growth region 576, and thein-growth region 576 may be attached to the articular portion 572 usingknown techniques, such as sintering are diffusion bonding.

FIG. 17 is a schematic block diagram of a computing device 600. Thecomputing device 600 is one example of a computer, server, mobiledevice, reader device, or equipment configuration which may be utilizedin connection with the system 200 illustrated in FIG. 2. The computingdevice 600 includes a processing device 602, an input/output device 604,memory 606, and operating logic 608. Furthermore, the computing device600 communicates with one or more external devices 610.

The input/output device 604 allows the computing device 600 tocommunicate with the external device 610. For example, the input/outputdevice 604 may be a network adapter, network card, interface, or a port(e.g., a USB port, serial port, parallel port, an analog port, a digitalport, VGA, DVI, HDMI, FireWire, CAT 5, or any other type of port orinterface). The input/output device 604 may be comprised of hardware,software, and/or firmware. It is also contemplated that the input/outputdevice 604 may include more than one of these adapters, cards, or ports.

The external device 610 may be any type of device that allows data to beinputted or outputted from the computing device 600. For example, theexternal device 610 may be a mobile device, a reader device, equipment,a handheld computer, a diagnostic tool, a controller, a computer, aserver, a printer, a display, an alarm, an illuminated indicator such asa status indicator, a keyboard, a mouse, or a touch screen display.Furthermore, it is contemplated that the external device 610 may beintegrated into the computing device 600. It is further contemplatedthat there may be more than one external device in communication withthe computing device 600.

The processing device 602 can be of a programmable type, a dedicated,hardwired state machine, or a combination of these; and can furtherinclude multiple processors, Arithmetic-Logic Units (ALUs), CentralProcessing Units (CPUs), Digital Signal Processors (DSPs) or the like.For forms of processing device 602 with multiple processing units,distributed, pipelined, and/or parallel processing can be utilized asappropriate. The processing device 602 may be dedicated to performanceof just the operations described herein or may be utilized in one ormore additional applications. In the depicted form, the processingdevice 602 is of a programmable variety that executes algorithms andprocesses data in accordance with operating logic 608 as defined byprogramming instructions (such as software or firmware) stored in memory606. Alternatively or additionally, the operating logic 608 forprocessing device 602 is at least partially defined by hardwired logicor other hardware. The processing device 602 can be comprised of one ormore components of any type suitable to process the signals receivedfrom input/output device 604 or elsewhere, and provide desired outputsignals. Such components may include digital circuitry, analogcircuitry, or a combination of both.

The memory 606 may be of one or more types, such as a solid-statevariety, electromagnetic variety, optical variety, or a combination ofthese forms. Furthermore, the memory 606 can be volatile, nonvolatile,or a combination of these types, and some or all of memory 606 can be ofa portable variety, such as a disk, tape, memory stick, cartridge, orthe like. In addition, the memory 606 can store data that is manipulatedby the operating logic 608 of the processing device 602, such as datarepresentative of signals received from and/or sent to the input/outputdevice 604 in addition to or in lieu of storing programming instructionsdefining the operating logic 608, just to name one example. As shown inFIG. 6, the memory 606 may be included with the processing device 602and/or coupled to the processing device 602.

The processes in the present application may be implemented in theoperating logic 608 as operations by software, hardware, artificialintelligence, fuzzy logic, or any combination thereof, or at leastpartially performed by a user or operator. In certain embodiments, unitsrepresent software elements as a computer program encoded on anon-transitory computer readable medium, wherein one or more of thecontrollers illustrated in connection with the system 200 performs thedescribed operations when executing the computer program.

Certain embodiments of the present disclosure relate to a methodcomprising: selecting a target porosity characteristic for a porousregion of an orthopedic device based at least in part upon a desiredperformance characteristic for the porous region; selecting an initialporosity characteristic based at least in part upon the target porositycharacteristic, wherein the initial porosity characteristic is greaterthan the target porosity characteristic; manufacturing an initial partusing an additive manufacturing procedure, wherein the initial partincludes a porous portion having the initial porosity characteristic;forming a deformed part from the initial part, wherein forming thedeformed part includes mechanically deforming at least a portion of theinitial part to form a deformed layer having the target porositycharacteristic; and forming the orthopedic device from the deformedpart, wherein forming the orthopedic device from the deformed partincludes forming the porous region from the deformed layer of thedeformed part.

In certain embodiments, forming the deformed part includes mechanicallydeforming at least a portion of the initial part using at least one offorging, rolling, and deep-drawing.

In certain embodiments, forming the deformed part includes mechanicallydeforming at least a portion of the initial part by striking the porousportion.

In certain embodiments, the additive manufacturing process includesbuilding the initial part on a build plate, and the method furthercomprises relieving stresses in the initial part with the initial partattached to the build plate.

In certain embodiments, building the initial part on the build plateincludes forming a plurality of layers, forming each layer includesscanning a beam along a bed of powdered raw material to form a melt pooland solidifying the melt pool, and the method further comprises removingthe initial part from the build plate after relieving stresses from theinitial part, and cleaning the initial part to remove loose powder fromthe initial part prior to forging the initial part.

In certain embodiments, the orthopedic device is an unfinishedorthopedic device, and the method further comprises finishing theunfinished orthopedic device, thereby forming a finished orthopedicdevice.

In certain embodiments, the forming the unfinished orthopedic devicefrom the deformed part comprises a molding procedure; the moldingprocedure comprises placing at least the deformed layer in a mold,infiltrating the deformed layer with a polymeric composition to form aninfiltrated layer within the deformed layer, and solidifying thepolymeric composition to form an attached part; and the attached part isattached to the deformed part by the solidified polymeric compositionwithin the infiltrated layer.

In certain embodiments, the polymeric composition comprises a liquidpolymeric composition, the attached part includes a smooth surface, themold has an internal surface corresponding to the smooth surface, themolding procedure comprises an injection molding procedure, andinfiltrating the deformed layer includes injecting the liquid polymericcomposition into the mold.

In certain embodiments, the attached part includes a smooth surface, themold has an internal surface corresponding to the smooth surface, themolding procedure comprises a compression molding procedure whichfurther includes placing the polymeric composition adjacent the internalsurface, and infiltrating the deformed region includes driving thedeformed layer toward the internal surface of the mold.

Certain embodiments of the present disclosure relate to a methodcomprising: manufacturing an initial part using an additivemanufacturing procedure, wherein the initial part includes a firstporous portion having an initial porosity characteristic; forging theinitial part to form a forged part, wherein the forging includesstriking an external surface of the initial part to form a forged regionfrom the first porous portion, and wherein the forged region includes adeformed layer having a target porosity characteristic lower than theinitial porosity characteristic; forming an unfinished orthopedic devicefrom the forged part; and forming a finished orthopedic device from theunfinished orthopedic device, the finished orthopedic device including aporous region formed of the deformed layer.

In certain embodiments, the method further comprises selecting thetarget porosity characteristic based at least in part upon a firstcriterion, and selecting the initial porosity characteristic based atleast in part upon the target porosity characteristic and a secondcriterion.

In certain embodiments, the first criterion relates to a desiredcharacteristic of the deformed layer, and the second criterion relatesto the additive manufacturing procedure.

In certain embodiments, the target porosity characteristic includes atarget pore size, the initial porosity characteristic includes aninitial pore size, the second criterion relates to a threshold pore sizefor the additive manufacturing procedure, and selecting the initialporosity characteristic based upon the target porosity characteristicand the second criterion includes selecting the initial pore sizegreater than each of the target pore size and the threshold pore size.

In certain embodiments, the target pore size includes an average targetpore size, and the initial pore size includes an average initial poresize.

In certain embodiments, the additive manufacturing procedure includesmelting a powder having a powder diameter to form a melt pool having amelt pool diameter, and the threshold pore size corresponds to at leastone of the powder diameter and the melt pool diameter.

In certain embodiments, the target average pore size is less than thethreshold pore size, and the initial average pore size is greater thanthe threshold pore size.

In certain embodiments, the forged region further includes a secondlayer formed from the first porous portion, the second layer having agreater porosity than the deformed layer.

In certain embodiments, forming the unfinished orthopedic device fromthe forged part comprises forming a molded part from the forged part andforming the unfinished orthopedic device from the molded part, themolded part includes the forged part and an attached part, forming themolded part includes infiltrating a polymeric composition into thedeformed layer and solidifying the liquid to form the attached part.

In certain embodiments, the first criterion relates to infiltration ofthe polymeric composition into the deformed layer, and selecting thetarget porosity characteristic includes selecting the target porositycharacteristic to discourage the polymeric composition from passingthrough the deformed layer into the second layer.

In certain embodiments, the finished orthopedic device includes atissue-facing surface defined by the second layer, the second layer hasthe initial porosity characteristic, and the second criterion relates totissue in-growth within the second layer.

In certain embodiments, the method further comprises generating a porousstructure model having the selected initial porosity characteristic, andthe additive manufacturing procedure includes building at least thefirst portion of the initial part according to the porous structuremodel.

Certain embodiments of the present disclosure relate to a method ofcreating an orthopedic device, the method comprising: manufacturing aninitial part using an additive manufacturing procedure, wherein theinitial part has a first outer surface and a second outer surface,wherein the initial part comprises a porous portion including a firstlayer defining the outer surface, a second layer defining the secondouter surface, and a plurality of pores having an initial average poresize; forming a forged part from the initial part, wherein forming theforged part includes forging the porous portion to form a forged region,wherein forging the porous portion includes deforming the first layer bystriking the first outer surface, thereby deforming the pores in thefirst layer, wherein the deformed first layer has a first layer averagepore size less than the initial average pore size, and wherein thesecond layer has a second layer average pore size greater than the firstlayer average pore size; forming an orthopedic device from the forgedpart, the orthopedic device including a tissue-facing region formed ofone of the first and second layers, wherein the tissue-facing region hasa tissue in-growth average pore size selected to promote in-growth oftissue in the tissue-facing region, and wherein the average pore size ofthe one of the first and second layers corresponds to the tissuein-growth average pore size.

In certain embodiments, the method further comprises selecting a targetaverage pore size based at least in part upon a first criterion, andselecting the initial average pore size based at least in part upon asecond criterion, wherein selecting the initial pore size includesselecting the initial pore size greater than the target average poresize, and wherein one of the first criterion and the second criterionrelates to tissue in-growth, and wherein the first layer average poresize corresponds to the target average pore size.

In certain embodiments, the tissue-facing region is formed of the firstlayer, the first criterion relates to tissue in-growth, and the secondcriterion relates to the additive manufacturing procedure.

In certain embodiments, the first layer average pore size is less than1000 microns, and the initial average pore size is greater than 1000microns.

In certain embodiments, the tissue-facing region is formed of the secondlayer, forming the orthopedic device from the forged part includesforming an attached part of the orthopedic device by infiltrating aliquid into the deformed first layer and solidifying the liquid, thefirst criterion relates to infiltration of the liquid, and the secondcriterion relates to tissue in-growth.

In certain embodiments, the target average pore size is less than 500microns, and the initial average pore size is less than 1000 microns.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiments have been shown and described and thatall changes and modifications that come within the spirit of theinventions are desired to be protected. It should be understood thatwhile the use of words such as preferable, preferably, preferred or morepreferred utilized in the description above indicate that the feature sodescribed may be more desirable, it nonetheless may not be necessary andembodiments lacking the same may be contemplated as within the scope ofthe invention, the scope being defined by the claims that follow. Inreading the claims, it is intended that when words such as “a,” “an,”“at least one,” or “at least one portion” are used there is no intentionto limit the claim to only one item unless specifically stated to thecontrary in the claim. When the language “at least a portion” and/or “aportion” is used the item can include a portion and/or the entire itemunless specifically stated to the contrary.

What is claimed is:
 1. A method, comprising: selecting a target porositycharacteristic for a porous region of an orthopedic device based atleast in part upon a desired performance characteristic for the porousregion; selecting an initial porosity characteristic based at least inpart upon the target porosity characteristic, wherein the initialporosity characteristic corresponds to a greater porosity than thetarget porosity characteristic; manufacturing an initial part includinga porous portion having the initial porosity characteristic; andmanufacturing a deformed part from the initial part, whereinmanufacturing the deformed part includes mechanically deforming at leasta portion of the initial part to form a deformed layer having the targetporosity characteristic.
 2. The method of claim 1, wherein themanufacturing of the initial part comprises using an additivemanufacturing procedure, the additive manufacturing process includesbuilding the initial part on a build plate; and wherein the methodfurther comprises relieving stresses in the initial part with theinitial part attached to the build plate.
 3. The method of claim 2,wherein building the initial part on the build plate includessuccessively forming a plurality of layers; wherein forming each layerincludes scanning a beam along a bed of powdered raw material to form amelt pool and solidifying the melt pool; and wherein the method furthercomprises: removing the initial part from the build plate afterrelieving stresses from the initial part; and cleaning the initial partto remove loose powder from the initial part prior to the mechanicallydeforming.
 4. The method of claim 1, further comprising forming theorthopedic device from the deformed part, wherein forming the orthopedicdevice from the deformed part includes forming the porous region fromthe deformed layer of the deformed part.
 5. The method of claim 4,wherein the orthopedic device is an unfinished orthopedic device; andwherein the method further comprises performing a finishing procedure onthe unfinished orthopedic device, thereby forming a finished orthopedicdevice.
 6. The method of claim 5, wherein the forming of the unfinishedorthopedic device from the deformed part comprises a molding procedure;wherein the molding procedure comprises placing at least the deformedlayer in a mold, infiltrating the deformed layer with a polymericcomposition to form an infiltrated layer within the deformed layer, andsolidifying the polymeric composition to form an attached part; andwherein the attached part is attached to the deformed part by thesolidified polymeric composition within the infiltrated layer.
 7. Themethod of claim 6, wherein the polymeric composition comprises a liquidpolymeric composition; wherein the attached part includes a smoothsurface; wherein the mold has an internal surface corresponding to thesmooth surface; wherein the molding procedure comprises an injectionmolding procedure; and wherein infiltrating the deformed layer includesinjecting the liquid polymeric composition into the mold.
 8. The methodof claim 6, wherein the attached part includes a smooth surface; whereinthe mold has an internal surface corresponding to the smooth surface;wherein the molding procedure comprises a compression molding procedurewhich further includes placing the polymeric composition adjacent theinternal surface; and wherein infiltrating the deformed region includesdriving the deformed layer toward the internal surface of the mold.
 9. Amethod, comprising: manufacturing an initial part including a firstporous portion having an initial porosity characteristic; forging theinitial part to form a forged part, wherein the forging includesstriking an external surface of the initial part to form a forged regionfrom the first porous portion, and wherein the forged region includes adeformed layer having a target porosity characteristic lower than theinitial porosity characteristic; and forming an orthopedic device fromthe forged part.
 10. The method of claim 9, further comprising selectingthe target porosity characteristic based at least in part upon a firstcriterion, and selecting the initial porosity characteristic based atleast in part upon the target porosity characteristic and a secondcriterion.
 11. The method of claim 10, wherein the first criterionrelates to a desired characteristic of the deformed layer; wherein thetarget porosity characteristic includes a target pore size; wherein theinitial porosity characteristic includes an initial pore size; whereinthe second criterion relates to a threshold pore size; and whereinselecting the initial porosity characteristic based upon the targetporosity characteristic and the second criterion includes selecting theinitial pore size greater than each of the target pore size and thethreshold pore size.
 12. The method of claim 11, wherein themanufacturing of the initial part comprises using an additivemanufacturing procedure; wherein the additive manufacturing procedureincludes melting a powder having a powder diameter to form a melt poolhaving a melt pool diameter; wherein the threshold pore size correspondsto at least one of the powder diameter and the melt pool diameter;wherein the target average pore size is less than the threshold poresize; and wherein the initial average pore size is greater than thethreshold pore size.
 13. The method of claim 9, wherein themanufacturing of the initial part comprises using an additivemanufacturing procedure.
 14. The method of claim 9, wherein the forgedregion further includes a second layer formed from the first porousportion, the second layer having a greater porosity than the deformedlayer; wherein forming the orthopedic device from the forged partcomprises forming a molded part from the forged part and forming theorthopedic device from the molded part; wherein the molded part includesthe forged part and an attached part; and wherein forming the moldedpart includes infiltrating a polymeric composition into the deformedlayer and solidifying the liquid to form the attached part.
 15. Themethod of claim 9, further comprising finishing the orthopedic device,the finished orthopedic device including a porous region formed of thedeformed layer; wherein the finished orthopedic device includes atissue-facing surface defined by a second layer formed from the firstporous portion, the second layer having a greater porosity than thedeformed layer; and wherein the second layer has the initial porositycharacteristic.
 16. A method of creating an orthopedic device, themethod comprising: manufacturing an initial part having a first outersurface and a second outer surface, wherein the initial part comprises aporous portion including a first layer defining the first outer surface,a second layer defining the second outer surface, and a plurality ofpores having an initial average pore size; and forming a forged partfrom the initial part, wherein forming the forged part includes forgingthe porous portion to form a forged region, wherein forging the porousportion includes deforming the first layer by striking the first outersurface, thereby deforming the pores in the first layer, wherein thedeformed first layer has a first layer average pore size less than theinitial average pore size, and wherein the second layer has a secondlayer average pore size greater than the first layer average pore size.17. The method of claim 16, further comprising selecting a targetaverage pore size based at least in part upon a first criterion, andselecting the initial average pore size based at least in part upon asecond criterion; wherein selecting the initial average pore sizeincludes selecting the initial average pore size greater than the targetaverage pore size; wherein one of the first criterion and the secondcriterion relates to tissue in-growth; and wherein the first layeraverage pore size corresponds to the target average pore size.
 18. Themethod of claim 16, further comprising forming an orthopedic device fromthe forged part, the orthopedic device including a tissue-facing regionformed of one of the first and second layers, wherein the tissue-facingregion has a tissue in-growth average pore size selected to promotein-growth of tissue in the tissue-facing region, and wherein the averagepore size of the one of the first and second layers corresponds to thetissue in-growth average pore size.
 19. The method of claim 16, whereinmanufacturing the initial part comprises using an additive manufacturingprocedure.